Fractures of bones, such as a fracture of a femur at one or more locations adjacent the head and neck of the femur are comparatively common. Many fracture reduction devices have been proposed for the reduction of fractures of this type. Such reduction devices basically consist of an elongate lag screw which is threaded on one end to be threadably received in the head of the femur. The lag screw is secured at the other end to a plate to form a compression hip screw assembly. The plate may include a barrel through which the screw passes. The fracture reduction device may also include bone screws for securing the plate to the femur.
The known reduction devices require that the lag screw first be inserted through an incision in a patient and into the canal of the femur. The lag screw is then advanced until the hip screw engages the head and/or neck of the femur proximal to the fracture site. The plate is then inserted through the incision and positioned over the lateral cortical wall of the shaft of the femur. At this time, the plate is assembled to the lag screw and the lag screw is tightened. When the lag screw is tightened, the head of the femur is forcibly compressed at the fracture line to the remainder of the femur. The screw may be permitted to slide in the barrel to place load on the fracture site under normal weight bearing. This sliding is known as sliding compression and promotes healing due to a phenomenon known as Wolff's law. Wolff's law teaches that load on the fracture site under normal weight bearing promotes healing and avoids atrophy of the fracture site.
Functionally, some of these devices perform quite satisfactorily for many fractures of the femur. Thus, while these devices have application and advantages relative one to another, problems and concerns remain with these devices. For example, the necessity to sequentially implant multiple components and then fit the components together results in added surgical time. As surgical time increases, costs and risks to the patient also increase.
Therefore, it would be advantageous to provide an improved hip screw assembly which is not only functional in providing the necessary stability and guidance in the reduction of the fracture, but can be efficiently, accurately and quickly implanted by the surgeon.